Python indentation

[Sateesh]

Hi,
I am a beginner in Python, and am wondering what is it about the indentation
in Python, without which python scripts do not work properly.
Why can't the indentation not so strict so as to give better freedom to the
user?
Is there any plausible reason behind this?

Cheers!
Sateesh

[Reinhold Birkenfeld]

Re: Python indentation

Sateesh wrote:[color=blue]
> Hi,
> I am a beginner in Python, and am wondering what is it about the indentation
> in Python, without which python scripts do not work properly.
> Why can't the indentation not so strict so as to give better freedom to the
> user?
> Is there any plausible reason behind this?[/color]

Yes. It's about readability.

In many languages, such as C or Perl, you can write readable code, but
you can also squeeze your code in as few lines as possible, resulting in
hard to read, hard to maintain, hard to debug code[1]. Whenever I
translate a Perl script into Python, I end up with about 25-40% more
lines, but the script is much more readable than the Perl counterpart
(mostly, of course, because of the lacking $'s ;).

Furthermore, most languages don't force indentation and use { } or
begin-end syntax. In Python, you have to indent your code properly,
which leads to clear structure.

I know how you feel when you are confronted with Python's indentation
system at first: Oh my god, the language is using significant
whitespace. As most of us come from a C background, an absolute
free-form language, this may seem like an unacceptable restraint, but as
you write code, it flows naturally, as if you ever hadn't written
something else. And, you don't have to write "end" :)

Reinhold

[1] This doesn't mean that you cannot write ununderstandabl e code in
Python... *grin*

--
Wenn eine Linuxdistributi on so wenig brauchbare Software wie Windows
mitbrächte, wäre das bedauerlich. Was bei Windows der Umfang eines
"kompletten Betriebssystems " ist, nennt man bei Linux eine Rescuedisk.
-- David Kastrup in de.comp.os.unix .linux.misc

[Brian Quinlan]

Re: Python indentation

Sateesh wrote:[color=blue]
> Why can't the indentation not so strict so as to give better freedom to the
> user?[/color]

Can you specify what desirable construction Python is denying you? Or
are you talking about freedom in the abstract?

Cheers,
Brian

[Sateesh]

Re: Python indentation

I surely understand the importance of indentation, but as you see there are
beautification tools that can be used to beautiy the C code. Also
indentation is based upon ones style of coding, and I feel somewhat
restricted when the language itself restricts someone to code in a
particular way.

Sateesh

"Brian Quinlan" <brian@sweetapp .com> wrote in message
news:mailman.61 .1089200252.513 5.python-list@python.org ...[color=blue]
> Sateesh wrote:[color=green]
> > Why can't the indentation not so strict so as to give better freedom to[/color][/color]
the[color=blue][color=green]
> > user?[/color]
>
> Can you specify what desirable construction Python is denying you? Or
> are you talking about freedom in the abstract?
>
> Cheers,
> Brian[/color]

[Brian Quinlan]

Re: Python indentation

Sateesh wrote:[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code.[/color]

I'm not sure why this is relevant.
[color=blue]
> Also indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.[/color]

Which is why I asked you to name a desirable code construction that
Python denies you due to it's indentation rules. If, for example, you
find the following style compelling:

if condition:
clause1
else:
clause2

Then Python is, indeed, restricting you. So could you provide an actual
example where Python is keeping you from using a style that you find
desirable?

Cheers,
Brian

[Jeff Epler]

Re: Python indentation

I doubt anybody but you has ever wondered about this, and if they have
the answers probably don't appear in a FAQ, the tutorial, "google"
or "google groups" searches, or any of the books published about the
Python language.

Jeff

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)

iD8DBQFA6+SlJd0 1MZaTXX0RAgKgAJ 9JwwpYkjy5DIGU6 p5QfK0m7/0lowCfeyDE
ncX4vs1DCCyfgHW 5GbCnUMk=
=y1+2
-----END PGP SIGNATURE-----

[Reinhold Birkenfeld]

Re: Python indentation

Sateesh wrote:[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code. Also
> indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.[/color]

That is what I wrote about. In the beginning, you think of the
indentation as a restriction. Later, you will be glad about it, and you
will not desire to structure your code otherwise.

Reinhold

--
Wenn eine Linuxdistributi on so wenig brauchbare Software wie Windows
mitbrächte, wäre das bedauerlich. Was bei Windows der Umfang eines
"kompletten Betriebssystems " ist, nennt man bei Linux eine Rescuedisk.
-- David Kastrup in de.comp.os.unix .linux.misc

[Brian Elmegaard]

Re: Python indentation

"Sateesh" <ext-sateesh.kavuri@ nokia.com> writes:
[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code. Also
> indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.[/color]

It is probably a matter of taste, but I don't like all the {} and ;
in c and the like.

Indentation in python may be done as you like, just keep it aligned
in the same block.

--
Brian (remove the sport for mail)

http://www.et.dtu.dk/staff/be

[Sateesh]

Re: Python indentation

I think I would be able to better appreciate Python after I go ahead with
some programming first.

Thanks for the insights!

Sateesh
"Brian Quinlan" <brian@sweetapp .com> wrote in message
news:mailman.62 .1089201328.513 5.python-list@python.org ...[color=blue]
> Sateesh wrote:[color=green]
> > I surely understand the importance of indentation, but as you see there[/color][/color]
are[color=blue][color=green]
> > beautification tools that can be used to beautiy the C code.[/color]
>
> I'm not sure why this is relevant.
>[color=green]
> > Also indentation is based upon ones style of coding, and I feel somewhat
> > restricted when the language itself restricts someone to code in a
> > particular way.[/color]
>
> Which is why I asked you to name a desirable code construction that
> Python denies you due to it's indentation rules. If, for example, you
> find the following style compelling:
>
> if condition:
> clause1
> else:
> clause2
>
> Then Python is, indeed, restricting you. So could you provide an actual
> example where Python is keeping you from using a style that you find
> desirable?
>
> Cheers,
> Brian[/color]

[Ville Vainio]

Re: Python indentation

>>>>> "Sateesh" == Sateesh <ext-sateesh.kavuri@ nokia.com> writes:

Sateesh> Why can't the indentation not so strict so as to give
Sateesh> better freedom to the user?

You already have all the freedom you need. You can indent with 1
space, or 56 spaces if that strikes your fancy. Why would you want the
freedom to indent inconsistently?

Sateesh> Is there any plausible reason behind this?

You should search the newsgroup archives (in google), there are
probably megabytes of discussion on this matter.

--
Ville Vainio http://tinyurl.com/2prnb

[Grant Edwards]

Re: Python indentation

On 2004-07-07, Reinhold Birkenfeld <reinhold-birkenfeld-nospam@wolke7.n et> wrote:
[color=blue][color=green]
>> I am a beginner in Python, and am wondering what is it about
>> the indentation in Python, without which python scripts do not
>> work properly. Why can't the indentation not so strict so as
>> to give better freedom to the user? Is there any plausible
>> reason behind this?[/color]
>
> Yes. It's about readability.
>
> In many languages, such as C or Perl, you can write readable code, but
> you can also squeeze your code in as few lines as possible, resulting in
> hard to read, hard to maintain, hard to debug code[1]. Whenever I
> translate a Perl script into Python, I end up with about 25-40% more
> lines, but the script is much more readable than the Perl counterpart
> (mostly, of course, because of the lacking $'s ;).[/color]

Compare C and Python:

In C, we have 10 lines

if (condition)
{
doThis();
doThat();
}
else
{
doWhatever();
andSoOn();
}

Which translates into 6 lines of Python:

if condition:
doThis()
doThat()
else:
doWhatever()
andSoOn()

Many fewer lines of space are wasted on delimiters. That means
you're more likely to have the entire logical "block" on the
screen at once. That means fewer bugs.

[Not to mention it takes about 1/4 to 1/3 of the actual lines
of code to accomplish the same amount of work.]

--
Grant Edwards grante Yow! Thank god!!... It's
at HENNY YOUNGMAN!!
visi.com

[Grant Edwards]

Re: Python indentation

On 2004-07-07, Sateesh <ext-sateesh.kavuri@ nokia.com> wrote:
[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code. Also
> indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.[/color]

All languages are restrictive. C requires blocks are delimited
by {} and statements by ;. Python isn't more restrictive, it
just has _different_ restrictions.

--
Grant Edwards grante Yow! What I want to find
at out is -- do parrots know
visi.com much about Astro-Turf?

[Peter Hansen]

Re: Python indentation

Ville Vainio wrote:
[color=blue][color=green][color=darkred]
>>>>>>"Satees h" == Sateesh <ext-sateesh.kavuri@ nokia.com> writes:[/color][/color]
> Sateesh> Why can't the indentation not so strict so as to give
> Sateesh> better freedom to the user?
>
> You already have all the freedom you need. You can indent with 1
> space, or 56 spaces if that strikes your fancy. Why would you want the
> freedom to indent inconsistently?[/color]

Oh, believe me, some people do want that (though, I hope, not
Sateesh... he sounds more sensible :-). I once had a fellow
working for me who, as it turned out, would indent effectively
arbitrary amounts each time he started a new block. We
were so astounded that several of us clustered around him to
watch him do it. He was quite amenable to the audience, too,
as he saw nothing wrong with it.

He would type (this was in C), say, an 'if' statement and its
expression. Then he would hit Enter and hold down the space
bar for a second or two. Generally he'd end up at least five
or ten spaces past the previous line's indentation. Sometimes
it was 25 spaces. The blocks for the 'if' and the 'else'
would rarely align, and if they did it was mere serendipity.

As it shortly turned out, the fellow was an iceberg, and
once we discovered the other 90% lurking below the surface,
and the seriously negative effect it had on his code (which
was all but unreadable to the rest of us, not to mention
just plain scary bad), we ditched him pretty quick.

The ironic thing is that he could just as easily have done
this with Python -- he was at least consistent within a
block...

-Peter

[Nikola Plejic]

Re: Python indentation

Sateesh wrote:[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code. Also
> indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.
>
> Sateesh
>[/color]

Huh, then C also limits you in a way... You have to constantly open and
close those curly braces. I'd be much better if I wouldn't have to do
that, but I have to get along with it (N.B. - I'm not a C programmer so
don't get me wrong :)).

Instead of { and } you have indentation... IMHO, that's a much more
"natural" way of defining blocks of code. You'll see, you'll get used to
it. It often results in writing *much* cleaner code in other languages,
too. At least in my case.

--
regards, [ mailto: zweistein at ftml dot net ]
Nikola [ http://hades.indivia.net/ ]

[Peter Maas]

Re: Python indentation

Sateesh schrieb:[color=blue]
> I surely understand the importance of indentation, but as you see there are
> beautification tools that can be used to beautiy the C code. Also
> indentation is based upon ones style of coding, and I feel somewhat
> restricted when the language itself restricts someone to code in a
> particular way.[/color]

You are only restricted if you want leading whitespace independent
from the block structure of your code. Formatting discussions among
C-Programmers concentrate on these topics:

1. How deep to indent:
this can be freely chosen in Python as well.

2. How to set brackets:
This issue is resolved automatically in Python. :)

Mit freundlichen Gruessen,

Peter Maas

--
-------------------------------------------------------------------
Peter Maas, M+R Infosysteme, D-52070 Aachen, Tel +49-241-93878-0
E-mail 'cGV0ZXIubWFhc0 BtcGx1c3IuZGU=\ n'.decode('base 64')
-------------------------------------------------------------------